(a) Field of the Invention
The invention relates to a cDNA probe for human methylenetetrahydrofolate reductase (MTHFR), and its uses.
(b) Description of Prior Art
Folic acid derivatives are coenzymes for several critical single-carbon transfer reactions, including reactions in the biosynthesis of purines, thymidylate and methionine. Methylenetetrahydrofolate reductase (MTHFR; EC 1.5.1.20) catalyses the NADPH-linked reduction of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a co-substrate for methylation of homocysteine to methionine. The porcine liver enzyme, a flavoprotein, has been purified to homogeneity; it is a homodimer of 77-kDa subunits. Partial proteolysis of the porcine peptide has revealed two spatially distinct domains: an N-terminal domain of 40 kDa and a C-terminal domain of 37 kDa. The latter domain contains the binding site for the allosteric regulator S-adenosylmethionine.
Hereditary deficiency of MTHFR, an autosomal recessive disorder, is the most common inborn error of folic acid metabolism. A block in the production of methyltetrahydrofolate leads to elevated homocysteine with low to normal levels of methionine. Patients with severe deficiencies of MTHFR (0-20% activity in fibroblasts) can have variable phenotypes. Developmental delay, mental retardation, motor and gait abnormalities, peripheral neuropathy, seizures and psychiatric disturbances have been reported in this group, although at least one patient with severe MTHFR deficiency was asymptomatic. Pathologic changes in the severe form include the vascular changes that have been found in other conditions with elevated homocysteine, as well as reduced neurotransmitter and methionine levels in the CNS. A milder deficiency of MTHFR (35-50% activity) has been described in patients with coronary artery disease (see below). Genetic heterogeneity is likely, considering the diverse clinical features, the variable levels of enzyme activity, and the differential heat inactivation profiles of the reductase in patients"" cells.
Coronary artery disease (CAD) accounts for 25% of deaths of Canadians. Cardiovascular risk factors (male sex, family history, smoking, hypertension, dyslipoproteinemia and diabetes) account for approximately 60 to 70% of the ability to discriminate CAD patients from healthy subjects. Elevated plasma homocysteine has also been shown to be an independent risk factor for cardiovascular disease.
Homocysteine is a sulfhydryl-containing amino acid that is formed by the demethylation of methionine. It is normally metabolized to cysteine (transsulfuration) or re-methylated to methionine. Inborn errors of metabolism (as in severe MTHFR deficiency) causing extreme elevations of homocysteine in plasma, with homocystinuria, are associated with premature vascular disease and widespread arterial and venous thrombotic phenomena. Milder elevations of plasma homocysteine (as in mild MTHFR deficiency) have been associated with the development of peripheral vascular disease, cerebrovascular disease and premature CAD.
Homocysteine remethylation to methionine requires the folic acid intermediate, 5-methyltetrahydrofolate, which is produced from 5,10-methylenetetrahydrofolate folate through the action of 5,10-methylenetetrahydrofolate reductase (MTHFR). Deficiency of MTHFR results in an inability to metabolize homocysteine to methionine; elevated plasma homocysteine and decreased methionine are the metabolic consequences of the block. Severe deficiencies of MTHFR (less than 20% of activity of controls) as described above, are associated with early-onset neurologic symptoms (mental retardation, peripheral neuropathy, seizures, etc.) and with atherosclerotic changes and thromboembolism. Milder deficiencies of MTHFR (35-50% of activity of controls), with a thermolabile form of the enzyme, are seen in patients with cardiovascular disease without obvious neurologic abnormalities.
In a survey of 212 patients with proven coronary artery disease, the thermolabile form of MTHFR was found in 17% of the CAD group and 5% of controls. In a subsequent report on 339 subjects who underwent coronary angiography, a correlation was found between thermolabile MTHFR and the degree of coronary artery stenosis. Again, traditional risk factors (age, sex, smoking, hypertension, etc.) were not significantly associated with thermolabile MTHFR. All the studies on MTHFR were performed by enzymatic assays of MTHFR in lymphocytes, with measurements of activity before and after heat treatment to determine thermolability of the enzyme.
Since 5-methyltetrahydrofolate, the product of the MTHFR reaction, is the primary form of circulatory folate, a deficiency in MTHFR might lead to other types of disorders. For example, periconceptual folate administration to women reduces the occurrence and recurrence of neural tube defects in their offspring. Neural tube defects are a group of developmental malformations (meningomyelocele, anencephaly, and encephalocele) that arise due to failure of closure of the neural tube. Elevated levels of plasma homocysteine have been reported in mothers of children with neural tube defects. The elevated plasma homocysteine could be due to a deficiency of MTHFR, as described above for cardiovascular disease.
Neuroblastomas are tumors derived from neural crest cells. Many of these tumors have been reported to have deletions of human chromosome region 1p36, the region of the genome to which MTHFR has been mapped. It is possible that MTHFR deletions/mutations are responsible for or contribute to the formation of this type of tumor. MTHFR abnormalities may also contribution to the formation of other types of tumors, such as colorectal tumors, since high dietary folate has been shown to be inversely associated with risk of colorectal carcinomas.
MTHFR activity is required for homocysteine methylation to methionine. Methionine is necessary for the formation of S-adenosylmethionine, the primary methyl donor for methylation of DNA, proteins, lipids, neurotransmitters, etc. Abnormalities in MTHFR might lead to lower levels of methionine and S-adenosylmethionine, as well as to elevated homocysteine. Disruption of methylation processes could result in a wide variety of conditions, such as neoplasias, developmental anomalies, neurologic disorders, etc.
Although the MTHFR gene in Escherichia coli (metF) has been isolated and sequenced, molecular studies of the enzyme in higher organisms have been limited without the availability of an eukaryotic cDNA.
It would be highly desirable to be provided with a cDNA probe for human methylenetetrahydrofolate reductase (MTHFR). This probe would be used for identification of sequence abnormalities in individuals with severe or mild MTHFR deficiency, including cardiovascular patients and patients with neurologic symptoms or tumors. The probe would also be used in gene therapy, isolation of the gene, and expression studies to produce the MTHFR protein. The probe would also provide the amino acid sequence of the human MTHFR protein, which would be useful for therapy of MTHFR deficiency by biochemical or pharmacological approaches.
It would be highly desirable to be provided with a molecular description of mutations in methylenetetrahydrofolate reductase deficiency.
Patients with sequence abnormalities in MTHFR might have different responses to drugs, possibly but not limited to drugs that affect folate metabolism. Therefore, it would be useful to know if these mutations are present before determining the appropriate therapy. The drugs/diseases for which this might be relevant include cancer chemotherapeutic agents, antibiotics, antiepileptic medication, antiarthritic medication, etc.
One aim of the present invention is to provide a cDNA probe for human methylenetetrahydrofolate reductase (MTHFR).
Another aim of the present invention is to provide a molecular description of mutations in methylenetetrahydrofolate reductase deficiency.
Another aim of the present invention is to provide a nucleic acid and amino acid sequence for human methylenetetrahydrofolate reductase.
Another aim of the present invention is to provide potential therapy for individuals with methylenetetrahydrofolate reductase deficiency.
Another aim of the present invention is to provide a system for synthesis of MTHFR protein in vitro.
A further aim of the present invention is to provide technology/protocol for identification of sequence changes in the MTHFR gene.
In accordance with one aspect of the present invention, there is provided a cDNA probe for human methylenetetrahydrofolate reductase (MTHFR) gene encoded by a nucleotide sequence as set forth in SEQ ID NO:1 or having an amino acid sequence as set forth in SEQ ID NO:2. The probe comprises a nucleotide sequence that hybridizes to the MTHFR nucleotide sequence, or an amino acid sequence that hybridizes to the MTHFR amino acid sequence.
In accordance with another aspect of the present invention, there is provided a method of diagnosis of methylenetetrahydrofolate reductase (MTHFR) deficiency in a patient with MTHFR deficiency. The method comprises the steps of amplifying a DNA sample obtained from the patient or reverse-transcripting a RNA sample obtained from the patient into a DNA and amplifying the DNA, and analyzing the amplified DNA to determine at least one sequence abnormality with respect to a human MTHFR encoded by a nucleotide sequence as set forth in SEQ ID NO:1 or having an amino acid sequence as set forth in SEQ ID NO:2, the sequence abnormality being indicative of MTHFR deficiency.
The sequence abnormality may comprise a mutation selected from a group consisting of 167G/A, 482G/A, 559C/T, 677C/T, 692C/T, 764C/T, 792+1G/A, 985C/T, 1015C/T, 1081C/T, 1298A/C and 1317T/C.
The selected mutation may consist of 677C/T.
The MTHFR deficiency may be associated with a disease, disorder, or dysfunction selected from a group consisting of cardiovascular disorders, cancer, osteoporosis, increased risk of occurrence of a neural tube defect in an offspring of said patient, neurological disorders, disorders influenced by folic acid metabolism, metabolic or endocrine disease, inborn errors of metabolism, inflammation, immune disorders, psychiatric illness, neoplastic disease and other related disorders, and renal disease.
The cancer may be selected-from a group consisting of neuroblastomas and colorectal carcinomas.
The disorder may consist of osteoporosis.
In accordance with yet another aspect of the present invention, there is provided a method for gene therapy of methylenetetrahydrofolate reductase (MTHFR) deficiency in a patient. The method comprises the steps of producing a recombinant vector for expression of MTHFR under the control of a suitable promoter, the MTHFR being encoded by a nucleotide sequence as set forth in SEQ ID NO:1 or having an amino acid sequence as set forth in SEQ ID NO:2, and transfecting the patient with the vector for expression of MTHFR.
In accordance with yet another aspect of the present invention, there is provided a human methylenetetrahydrofolate reductase (MTHFR) protein encoded by a nucleotide sequence as set forth in SEQ ID NO:1 or having an amino acid sequence as set forth in SEQ ID NO:2.
In accordance with yet another aspect of the present invention, there is provided a recombinant human methylenetetrahydrofolate reductase (MTHFR) protein encoded by a nucleotide sequence as set forth in SEQ ID NO:1 or having an amino acid sequence as set forth in SEQ ID NO:2.
In accordance with yet another aspect of the present invention, there is provided a method of treatment of MTHFR-deficiency in a patient that comprises administering such a MTHFR protein.
The MTHFR deficiency may be associated with a cancer.
The cancer may be selected from a group consisting of neuroblastomas and colorectal carcinomas.
In accordance with yet another aspect of the present invention, there is provided a method of preventing an occurrence of a neural tube defect in an offspring of a patient. The method comprises administering to the patient such a MTHFR protein.
In accordance with yet another aspect of the present invention, there is provided a method for determining drug susceptibility, drug response or drug toxicity of a patient having a methylenetetrahydrofolate reductase (MTHFR) deficiency. The method comprises the steps of amplifying a DNA sample obtained from the patient or reverse-transcripting a RNA sample obtained from the patient into a DNA and amplifying said DNA, analyzing the amplified DNA to determine a sequence abnormality in a MTHFR sequence, the MTHFR sequence being encoded by a nucleotide sequence as set forth in SEQ ID NO:1 or having an amino acid sequence as set forth in SEQ ID NO:2, and administering the drug to the patient and determining the sequence abnormality associated with the patient susceptibility, response or toxicity to the drug. Further, in human therapeutic approaches, both pharmacokinetics and pharmacodynamics may be influenced by folic acid metabolism. Pharmacokinetics includes, but is not excluded to, factors such as absorption, distribution, metabolism, and excretion. Other considerations include safety and toxicity. Examples of toxicities from therapeutics include, but are not limited to, blood dyscrasias, cutaneous toxicities, systemic toxicity, CNS toxicity, hepatic toxicity, cardiovascular toxicity, pulmonary toxicity, and renal toxicity.
The sequence abnormality may comprise a mutation selected from a group consisting of 167G/A, 482G/A, 559C/T, 677C/T, 692C/T, 764C/T, 792+1G/A, 985C/T, 1015C/T, 1081C/T, 1298A/C and 1317T/C and the drug may be selected from a group consisting of cancer chemotherapeutic agents, antibiotics, antiepileptic agents, antiarthritic agents, and anti-inflammatory agents. Examples of chemotherapeutic agents include alkylating agents (nitrogen mustards, ethylenimines and methylmelamines, alkyl sulfonates, nitrosoureas, triazenes), antimetabolites (folic acid analogs, pyrimidine analogs, purine analogs and related inhibitors), and natural products (vinca alkyloids, epipodophyllotoxins, antibiotics, enzymes, biological response modifiers). Examples of anti-inflammatory agents include non-steroidal anti-inflammatory agents, steroids, antihistaminergics, 5-LO inhibitors, cytokine agonists, and cytokine antagonists. The drug may also include therapies for metabolic or endocrine disease such as hormone agonists and antagonists, intracellular response modifiers, and secretegogues. Other possible drugs include therapies for cardiovasular disease or disorders such as antianemic, antiangina, antiarrythmics, antihypertensives, positive inotropic agents, and antithrombotics. The drug may also be a therapy for an immune disorder, such as immune modulators, immunosuppression agents, and immunostimulation agents. Additionally, any other drug for the treatment of a metabolic disease, inborn errors of metabolism, psychiatric disorders, neoplastic disease and other related disorders, and renal disease is relevant to the invention
The MTHFR deficiency may be associated with a disorder selected from a group consisting of cardiovascular disorders, coronary and arterial disorders, neurological disorders, increased risk of occurrence of a neural tube defect in an offspring, cancer, osteoporosis and other disorders influenced by folic acid metabolism.
In accordance with yet another aspect of the present invention, there is provided a method of treatment of a patient having a cancer comprising the step of inhibiting gene expression for a MTHFR protein or a mRNA produced form the gene.
In accordance with yet another aspect of the present invention, there is provided a method of treatment of a patient having a cancer comprising the step of inhibiting the MTHFR protein.
The use of MTHFR alleles as diagnostic, therapeutic, prognostic, and pharmacogenomic markers may also be applied to neurological disorders such as psychoses and to other diseases and disorders that may be treated with anti-psychotic therapeutics. The presence of particular MTHFR alleles may be used to predict the safety and efficacy of a particular therapy and to select preferred therapies for these subjects.
Accordingly, in one aspect, the invention provides a method of diagnosing a psychosis in a subject. This method involves analyzing the MTHFR nucleic acid in a sample obtained from the subject and determining the presence of at least one heterozygous MTHFR mutant allele in the subject that is indicative of the subject having the psychosis.
In a related aspect, the invention features a method of determining a risk for a psychosis or a propensity for a psychosis in a subject. This method includes analyzing the MTHFR nucleic acid in a sample obtained from said subject and determining the presence of at least one heterozygous MTHFR mutant allele in the subject that is indicative of the risk for a psychosis or the propensity for a psychosis in the subject.
In another aspect, the invention provides a method of diagnosing a psychosis in a subject. This method involves analyzing the MTHFR nucleic acid in a sample obtained from the subject and determining the presence of a heterozygous MTHFR mutation at position 677 and/or the presence of at least one other MTHFR mutation at a position other than 677. These mutations are indicative of the subject having the psychosis.
The invention also provides a related method of diagnosing a risk for a psychosis or a propensity for a psychosis in a subject. This method includes analyzing the MTHFR nucleic acid in a sample obtained from the subject and determining the presence of a heterozygous MTHFR mutation at position 677 and the presence of at least one other MTHFR mutation at a position other than 677. These mutations are indicative of the risk for a psychosis or the propensity for a psychosis in the subject.
In addition to their use in diagnosing a psychosis or an increased risk for a psychosis, the determination of one or more mutations in an MTHFR allele may also be used to classify subjects into a subgroup for a clinical trial of an anti-psychotic therapy, to determine a preferred anti-psychotic therapy for a subject, or to determine whether the MTHFR mutations are indicative of a response to an anti-psychotic therapy.
Accordingly, the invention also provides a method for stratification of subjects involved in a clinical trial of an anti-psychotic therapy. This method involves analyzing the MTHFR nucleic acid in a sample obtained from a subject and determining before, during, or after the clinical trial the presence of at least one MTHFR mutant allele in the subject that places the subject into a subgroup for the clinical trial. In one preferred embodiment, the anti-psychotic therapy is a therapy for schizophrenia.
In another aspect, the invention provides a method for selecting a therapy for a subject suffering from a psychosis. This method include analyzing the MTHFR nucleic acid in a sample obtained from the subject and determining the presence of at least one MTHFR mutant allele in the subject that is indicative of the safety or efficacy of the therapy.
In yet another aspect, the invention features a method for determining whether a mutant MTHFR allele is indicative of a response to a therapy for a psychosis. This method includes (a) determining whether the response of a first subject or set of subjects at increased risk for or diagnosed with the psychosis differs from the response of a second subject or set of subjects at increased risk for or diagnosed with the psychosis, (b) analyzing the MTHFR nucleic acid in a sample obtained from the first and second subjects or sets of subjects, and (c) determining whether at least one MTHFR mutant allele differs between the first and second subjects or sets of subjects. If the MTHFR mutant allele is correlated to a response to the therapy, the mutant allele is determined to be indicative of the safety or efficacy of the therapy.
The invention also provides a method for preventing, delaying, or treating a psychosis in a subject. This method includes (a) analyzing the MTHFR nucleic acid in a sample obtained from the subject, (b) determining the presence of at least one MTHFR mutant allele in the subject that is predictive of the safety or efficacy of at least one anti-psychotic therapy, (c) determining a preferred therapy for the subject, and (d) administering the preferred therapy to the subject.
In another aspect, the invention provides a pharmaceutical composition including a compound which has a differential effect in subjects having at least one copy of a particular MTHFR allele and has a pharmaceutically acceptable carrier, excipient, or diluent. This compound is preferentially effective to treat a subject having the particular MTHFR allele. In a preferred embodiment, the composition is adapted to be preferentially effective based on the unit dosage, presence of additional active components, complexing of the compound with stabilizing components, or inclusion of components enhancing delivery or slowing excretion of the compound. In another preferred embodiment, the compound is deleterious to subjects having at least one copy of the particular MTHFR allele or in subjects not having at least one copy of the particular MTHFR allele, but not in both. In yet another preferred embodiment, the subject suffers from a disease or condition selected from the group consisting of amyotrophic lateral sclerosis, anxiety, dementia, depression, epilepsy, Huntington""s disease, migraine, demyelinating disease, multiple sclerosis, pain, Parkinson""s disease, schizophrenia, psychoses, and stroke. In still another preferred embodiment, the pharmaceutical composition is subject to a regulatory restriction or recommendation for use of a diagnostic test determining the presence or absence of at least one particular MTHFR allele. In another preferred embodiment, the pharmaceutical composition is subject to a regulatory limitation or recommendation restricting or recommending restriction of the use of the pharmaceutical composition to subjects having at least one particular MTHFR allele. In yet another preferred embodiment, the pharmaceutical composition is subject to a regulatory limitation or recommendation indicating the pharmaceutical composition is not to be used in subjects having at least one particular MTHFR allele. In still another preferred embodiment, the pharmaceutical composition is packaged, and the packaging includes a label or insert restricting or recommending the restriction of the use of the pharmaceutical composition to subjects having at least one particular MTHFR allele. In yet another embodiment, the pharmaceutical composition is packaged, and the packaging includes a label or insert requiring or recommending the use of a test to determine the presence or absence of at least one particular MTHFR allele in a subject. Preferably, the compound is an anti-psychotic therapy, such as a therapy for schizophrenia.
In preferred embodiments of each of the aspects of the invention, the mutant MTHFR allele encodes an MTHFR protein with reduced activity or reduced thermal stability. It is also contemplated that the MTHFR protein may have a reduced half-life. Preferably, the MTHFR mutation is a missense mutation. Preferred MTHFR mutations include a G/A mutation at position 167, a G/A mutation at position 482, a C/T mutation a position 559, a C/T mutation at position 677, a C/T mutation at position 692, a C/T mutation at position 764, a G/A mutation at position 792+1, a C/T mutation at position 985, a C/T mutation at position 1015, a C/T mutation at position 1081, an A/C mutation at position 1298, and a T/C mutation at position 1317. It is also contemplated that the mutations at these positions may involve changes to other nucleotides. In other preferred embodiments, the subject has at least two MTHFR mutant alleles. Preferably the two or more mutant MTHFR alleles have at least one of the following: a G/A mutation at position 167, a G/A mutation at position 482, a C/T mutation a position 559, a C/T mutation at position 677, a C/T mutation at position 692, a C/T mutation at position 764, a G/A mutation at position 792+1, a C/T mutation at position 985, a C/T mutation at position 1015, a C/T mutation at position 1081, an A/C mutation at position 1298, or a T/C mutation at position 1317. In yet other preferred embodiments, the MTHFR mutation results in a change in the amino acid at position 226 of the encoded protein from alanine found in wild-type MTHFR to any other amino acid, including valine or residues other than valine. In still other preferred embodiments, the mutation results in a change in amino acid 433 of the encoded protein from glutamic acid to any other amino acid, including alanine or residues other than alanine. When two mutations are present at different nucleotide positions, the mutations may be in the same or different MTHFR alleles. The MTHFR mutation may, without limitation, also be an insertion, deletion, or frameshift mutation.
Preferably, the psychosis being diagnosed or treated is schizophrenia. The psychosis may also be any other psychosis such as manic-depressive disease, depression with psychotic features, organic psychotic disorders, psychosis in alcohol or drug intoxication, postinfection psychosis, postpartum psychosis, senile psychosis, traumatic psychosis, manic-depressive psychosis, psychosis from toxic agents, and acute idiopathic psychotic illnesses.
The use of MTHFR alleles as diagnostic, therapeutic, prognostic, and pharmacogenomic markers may also be applied to other neurological disorders. Examples of neurological disorders include, but are not limited to, mood disorders, neurodegenerative diseases, cognitive disorders, seizure disorders such as epilepsy, headaches such as migraines, pain associated with the central nervous system, demyelinating diseases, spasticity, neural tube defects, neurofibromatosis, and ischemic cerebrovascular diseases such as thrombotic and hemorrhagic strokes. Mood disorders include but are not excluded to conditions such as unipolar depression, bipolar depression and anxiety. Examples of neurodegenerative diseases include amyotrophic lateral sclerosis, Parkinson""s disease, acquired or symptomatic parkinsonism, Huntington""s disease, and heredodegenerative disease. Examples of cognitive disorders include dementia, dementia of the Alzheimer""s type, vascular dementia, multi-infarct dementia and posttraumatic dementia. Demyelinating diseases consist of diseases such as the following: multiple sclerosis (MS), Marburg and Balo forms of MS, neuromyelitis optica, perivenous encephalitits, acute disseminated encephalomyelitits, and acute necotizing hemmorhhagic encephalitis.
The methods of the invention may also be applied to non-psychiatric conditions for which anti-psychotic drugs are used. Examples of these conditions include nausea, vomiting, movement disorders associated with neurodegenerative diseases such as Huntington""s disease and Tourette""s syndrome, pruritis, and chronic hiccough. Cardiovascular disorders, cancers, neoplastic disease and other related disorders, osteoporosis, neural tube defects, neurological disorders, disorders influenced by folic acid metabolism, metabolic or endocrine disease, inborn errors of metabolism, inflammation, immune disorders, psychiatric illness, and renal disease are also relevant to these methods.
It is to be understood that the methods of the invention may be applied to any other diseases or disorders. Examples of other diseases or disorders may include those that are indirectly or directly affected by an increase or decrease in MTHFR activity, homocysteine levels, methionine levels, S-adenosylmethionine activity, or methylation.
The therapies relevant to the methods of the present invention include all clinically used therapies and therapies in preclinical or clinical development for the aforementioned diseases and disorders. Preferred therapies include the therapies listed in databases such as Life Cycle, RandD Focus, IMS World Publications, London UK or in any other database of therapies that are in development and/or that are FDA approved. Preferred anti-psychotic therapies include conventional neuroleptics such as phenothiazines (e.g. chlorpromazine), thioxanthenes (e.g. thiothixene), butyrophenones (e.g. haloperidol, one of the most useful conventional anti-psychotics), dibenzoxazepines, dibenzodiazepines, diphenylbutylpiperidines, and other heterocyclic compounds. Preferred atypical neuroleptics include compounds such as clozaril, risperidone, olanzapine, quetiapine, ziprasidone, amisulpride, sertindole, and iloperidone. Additionally, anti-psychotic therapies, such as loxapine, may have pharmacology intermediate between that of conventional and atypical neuroleptics. In preferred embodiments, the treatment or prevention of a neurological disease includes administration of one or more therapeutically active compounds that bind to a dopamine, histamine, muscarinic cholinergic, xcex1-adrenergic, or serotonin receptors.
Examples of other pharmaceutically active compounds which may be used as anti-psychotics include synthetic organic molecules, naturally occurring organic molecules, nucleic acid molecules, biosynthetic proteins or peptides, naturally occurring peptides or proteins, and modified naturally occurring peptides or proteins. In preferred embodiments, the preferred therapy consists of an altered dose regime compared to other clinically used dose regimes or to the administration of a combination of therapeutics. It is also contemplated that the preferred therapy may consist of other medical treatments, such as surgical procedures, electroconvulsive therapy, or psychotherapy. Examples of psychotherapies include dynamic psychotherapy, cognitive-behavioral therapy, interpersonal therapy, behavioral therapy, group psychotherapy, and family therapy. For the administration of a therapeutically active compound to a subject, any mode of administration or dosing regime may be used. It is to be understood that for any particular subject, specific dosage regimes should be adjusted over time according to the individual need and the professional judgment of the person administering or supervising the administration of the compositions.
Descriptions of clinically used therapies (for example, for psychosis) and guidelines for their use are readily available in common references such as the Physicians Desk Reference (PDR). Additionally, therapeutics are described and listed in medical, pharmacy, and pharmacology journals and textbooks, such as Goodman and Gilman""s The Pharamcological Basis of Therapeutics, (Hardman and Limbird (eds.) Ninth Edition, McGraw-Hill, New York, 1996). Additional information on FDA approved therapeutics and therapies in clinical trials for particular indications, diseases, or disorders may be easily found in electronic databases available through subscription and pharmaceutical company information.
By xe2x80x9cpreferred therapyxe2x80x9d is meant a therapy for a disease, disorder, or dysfunction that is efficacious, safe, and/or has reduced toxicity compared to another therapy for the disease or disorder. The preferred therapy selected based on one or more mutations in one or more MTHFR alleles is preferably effective in at least 20, 30, 50, 70, or 90% of the subjects having the MTHFR mutation(s). By xe2x80x9ceffectivexe2x80x9d is meant ablates, reduces, or stabilizes symptoms in a subject suffering from a disease, disorder, or dysfunction prevents the onset of symptoms in a subject at risk for a disease, disorder, or dysfuction, or results in a later age-at-onset of symptoms in the subject compared to the average age-at-onset for the corresponding untreated subjects with the same MTHFR mutation(s). The effectiveness of the therapy for the treatment of a psychosis may be evaluated based on the Clinical Global Impression (CGI), Diagnostic Interview for Genetic Studies (DIGS), Global Assessment Score (GAS), or Brief Psychiatric Rating Scale (BPRS) using standard procedures. Preferably, the total PPRS score is lowered by 5, more preferably 10, and most preferably 15 points. By xe2x80x9creduced toxicityxe2x80x9d is meant lower level of adverse pharmacological or physiological effects. Preferably, the therapy produces clinically unacceptable side-effects in 5, 10, 20, 30, or 50% fewer of the subjects having the MTHFR mutations(s) than in subjects who do not have one or ore of the MTHFR mutations.
A xe2x80x9cpolymorphismxe2x80x9d is intended to mean a mutation or allelic variance present in 1% or more of alleles of the general population. A polymorphism is disease-causing when it is present in patients with a disease but not in the general population. However, a polymorphism present both in patients having a disease and in the general population is not necessarily benign. The definition of a disease-causing substitution, as distinct from a benign polymorphism, is based on 3 factors: (1) absence of the change in at least 50 independent control chromosomes; (2) presence of the amino acid in the bacterial enzyme, attesting to its evolutionary significance and (3) change in amino acid not conservative. Although expression of the substitutions is required to formally prove that they are not benign, the criteria above allow us to postulate that the changes described in this report are likely to affect activity.